| Gunshot residue (GSR) is often important in cases that involve firearms. Over the years, scientists have developed methods for detecting GSR on a shooter's hands, a victim, or any object that may have been within six feet of the firearm. However, when the weapon is more than six feet from the target, gun powder residue may not be present. The only residue that may be present is bullet wipe, material that is transferred from the surface of the bullet as it penetrates the target.;Laser Induced Breakdown Spectroscopy (LIBS) is used to identify the elemental composition of an unknown material. Areas as small as 2 mm2 can be analyzed, making it an ideal method for the analysis of the minute residues left by a bullet. The objective of this research is to determine the possibility of using Laser Induced Breakdown Spectroscopy (LIBS) as a presumptive test of bullet wipe produced by lead-free bullets. Four materials, cotton, wood, drywall, and cement, were shot with three different brands of lead-free cartridges. To detect the bullet wipe, the samples were analyzed for copper, lead, and barium. The analysis was performed using addLIBS software and NIST Atomic Spectra Database. Bullet wipe was successfully detected in the cotton, wood, and drywall, but not the cement block. |
